I’ve had one (2) of those hanging on my shop wall for about five years. Was given to me by a friend, neither one of us could figure it out. It’s missing the bolt to pull the sections together. Seeing your picture gives me the missing info on how to use this thing. Thanks, can’t wait to try it!

I have an old, but very servicable Stanley picture frame vise. Its cast iron and still does a good job. The only drawback is that I wish I had three more so I could do a picture frame all in one gluing operation.